Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/509828

The future of a partially effective HIV vaccine: assessing limitations at the population level

Selinger, C.·Dimitroff, D. T.·Welkhoff, P.·Bershteyn, A.
View original source ↗Export metadata ↓

Abstract

ObjectivesMathematical models have unanimously predicted that a first-generation HIV vaccine would be useful and cost-effective to roll out, but that its overall impact would be insufficient to reverse the epidemic. Here, we explore what factors contribute most to limiting the impact of such a vaccine.\n\nMethodsRanging from a theoretical ideal to a more realistic regimen, mirroring the one used in the currently ongoing trial in South Africa (HVTN 702), we model a nested hierarchy of vaccine attributes such as speed of roll-out, efficacy, and retention of booster doses.\n\nResultsThe predominant reasons leading to a substantial loss of vaccine impact on the HIV epidemic are the time required to scale up mass vaccination, limited durability and waning of efficacy.\n\nConclusionsA partially effective HIV vaccine will be a critical milestone for the development of a highly effective, durable, and scalable next-generation vaccine. Accelerated development, expedited vaccine availability, and improved immunogenicity are the main attributes of a vaccine that could dramatically reverse the course of the epidemic in highly endemic countries.

Source connections

Explore related subjects

epidemiologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Selinger, C., Dimitroff, D. T., Welkhoff, P., Bershteyn, A.. 2019-01-04. The future of a partially effective HIV vaccine: assessing limitations at the population level. https://doi.org/10.1101/509828

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2019

Modeling cholera transmission and vaccination in a refugee camp

BackgroundCholera remains a major public health concern, particularly in refugee camps, which may contend with overcrowding and scarcity of resources. Maela, the largest long-standing refugee camp in Thailand, experienced four cholera outbreaks between 2005 and 2010. In 2013, a cholera vaccine campaign was implemented in the camp. To assist in the evaluation of the campaign and planning for subsequent campaigns, we developed a mathematical model of cholera in Maela. MethodsWe formulated a Susceptible-Infectious-Water-Recovered-based cholera transmission model and estimated parameters using incidence data from 2010. We next evaluated the reduction in cases conferred by several immunization strategies, varying timing, effectiveness, and resources (i.e., vaccine availability). Finally, we generated post-campaign case forecasts, to determine whether a booster campaign was needed. ResultsWe found that preexposure vaccination can substantially reduce the risk of cholera even when the < 50% of the population is given the full two-dose series. Additionally, the preferred number of doses per person should be considered in the context of one vs. two dose effectiveness and vaccine availability. For reactive vaccination, a trade-off between timing and effectiveness was revealed, indicating that it may be beneficial to give one dose to more people rather than two doses to fewer people, given that a two-dose schedule would incur a delay in administration of the second dose. Forecasting using realistic coverage levels predicted that there was no need for a booster campaign in 2014 (consistent with our predictions, there was not a cholera epidemic in the 2014 season). ConclusionsOur analyses suggest that vaccination in conjunction with ongoing water sanitation and hygiene efforts provides an effective strategy for cholera outbreaks in refugee camps. Effective preexposure vaccination depends on timing and effectiveness. If a camp is facing an outbreak, delayed distribution of vaccines can substantially alter the effectiveness of reactive vaccination, suggesting that quick distribution of vaccines may be more important than ensuring every individual receives both vaccine doses.

epidemiology↗
bioRxiv2019

Prevalence and risk factors of postpartum depression among women living in urban slums of Dhaka, Bangladesh

Postpartum depression (PPD) is a serious pubic health concern and known to have the adverse effects on mothers perinatal wellbeing; and childs physical and codnitive development. There were limited literatures on PPD in Bangladesh, especially in urban slum context. The aim of this study was to assess the burden and risk factors of PPD among the urban slum women. A cross-sectional study was conducted between November-December 2017 in three urban slums on 376 women within first 12 months of postpartum. A validated Bangla version of Edinburgh Postnatal Depression Scale was used to measure the depression status. Respondents socio-economic characteristics and other risk factors were collected with structured validated questionaire by trained interviewers. Unadjusted Prevalence Ratio (PR) and Adjusted Prevalence Ratio (APR) were estimated with Generalized Linear Model(GLM) and Generalized Estimating Equation (GEE) respectively to identify the risk factors of PPD. The prevalence of PPD was 39.4% within first 12 months following the child birth. Job involvement after child delivery (APR=1.9, 95% CI= 1.1, 3.3), job loss due to pregnancy (APR=1.5, 95% CI= 1.0, 2.1), perinatal and postnatal death (APR=1.4, 95% CI= 0.97, 2.0), unintended pregnancy (APR=1.8, 95% CI= 1.3, 2.5), management of delivery cost by borrowing, selling or mortgaging assets (APR=1.3, 95% CI= 0.94, 1.9), depressive symptom during pregnancy (APR=2.5, 95% CI= 1.7, 3.8) and intimate partner violence (APR=2.0, 95% CI= 1.2, 3.3), were identified as risk factors. PPD was not associated with poverty, mother in law and any child related factors. The burden of postpartum depression is high in the urban slum of Bangladesh. Maternal mental health services should be integrated with existing maternal health services. Research is required for the innovation of effective, low cost and culturally appropriate PPD case management and preventive intervention in urban slum of Bangladesh.

epidemiology↗
bioRxiv2019

Plasmodium caprae infection is negatively correlated with infection of Theileria ovis and Anaplasma ovis in goats

Theileria, Babesia, and Anaplasma are tick-borne pathogens affecting livestock industries worldwide. In this study, we surveyed the presence of Babesia ovis, Theileria ovis, Theileria lestoquardi, Anaplasma ovis, Anaplasma phagocytophilum, and Anaplasma marginale in 200 goats from 3 different districts in Sistan and Baluchestan province, Iran. Species-specific diagnostic PCR and sequence analysis revealed that 1.5%, 12.5%, and 80% of samples were positive for T. lestoquardi, T. ovis, and A. ovis, respectively. Co-infections of goats with up to 3 pathogens were seen in 22% of the samples. We observed a positive correlation between A. ovis and T. ovis infection. In addition, by analyzing the data with respect to Plasmodium caprae infection in these goats, a negative correlation was found between P. caprae and A. ovis and between P. caprae and T. ovis. This study contributes to understanding the epidemiology of vector-borne pathogens and their interplay in goats.\n\nImportanceTick-borne pathogens include economically important pathogens restricting livestock farming worldwide. In endemic areas livestock are exposed to different tick species carrying various pathogens which could result in co-infection with several tick-borne pathogens in a single host. The co-infection and interaction among pathogens are important in determining the outcome of disease. Little is known about pathogen interactions in the vector and the host. In this study, we show for the first time that co-infection of P. caprae, a mosquito transmitted pathogen, with T. ovis and A. ovis. Analysis of goat blood samples revealed a positive correlation between A. ovis and T. ovis. Moreover, a negative correlation was seen between P. caprae, a mosquito transmitted pathogen, and the tick-borne pathogens T. ovis or A. ovis.

epidemiology↗